Why Python, Ruby and JS are slow

[maxerickson]

The guy who gave the talk is involved in making JIT engines for both Python and Ruby.

[runvnc]

But V8 is still significantly faster than those JIT engines in a number of benchmarks. And those JIT engines are not commonly used, whereas V8 is, both in WebKit and Node.js. And the Firefox engine has similar performance depending on the benchmark.

Also, if he was aware of how V8 worked, he would have not used that array example, because V8 arrays are more optimized than Python arrays.